I had mine replaced, and the mechanic did not do a relearn, so far so good.
If you happen to have an I-Phone, and 170.00 you could invest in Dash Boss, it has the ability to do case learns.
I have not gotten it yet, but plan to try it out on my 96 park Ave when I get the money.
It is not mentioned to work with any pre 2003 vehicles, but you can use this page to know how to check if you have the right pins for CAN.
DashBoss / DOWNLOADS AND UPDATES